German bassist Peter Kowalds peripatetic life and willingness to improvise with musicians of all stripes and nationalities immensely widened the circle of musicians who mourned his sudden death from a heart attack at 58, in September 2002.

His enthusiasm for musical collaboration, which seemed to augment in the year or so before his death — a characteristic he shared with other first generation European improvisers such as Peter Brötzmann, Evan Parker and Derek Bailey — has meant that a raft of recent CDs have celebrated the bassists skills. Although not one is the definite last session, MA is one of the more impressive efforts.

Thats because it has elements of both familiarity — his linkage with Israeli-born, Brooklyn-based reedman Assif Tsahar, with whom Kowald had recorded in the past — and freshness, since its the first and last meeting between the bassist and veteran American Sunny Murray, drummer on the Albert Ayler LPs Kowald so admired as an apprentice Free Jazzer in Wuppertal.

DEAR PETER on the other hand, recorded in Rome a little more than a month after the bassists passing, is a celebration of Kowalds achievements though non-specific improvisations. Rather than featuring a bassist trying to replicate his style, the trio involved includes a fellow German, veteran drummer Martin Blume; Italian saxophonist Mario Schiano, who has intersected with German, British and other improvisers since the 1970s; and Chinese-born, Berlin resident Xu Fengxia on guzheng and voice, whose improv partners have included German multi-reedist Wolfgang Fuchs and American bassist Joe Fonda.

As a matter of interest, MA, recorded live in Barcelona, Spain, two months before Kowalds death, is cast in the classic Ayler Trio mould, with one more than 70 minute instant composition divided on disc into seven tracks for easier playback.

More discordant than melodic, Tsahar, 33, spends most of the CD on tenor saxophone advancing the type of screeching slipsliding sounds Ayler brought to jazz. His bass clarinet improvisations are harsh as well, but with an undercurrent of buzzing melody that peeps through every so often to mate with Kowalds unvarying rhythmic pulse. Senior citizen Murray, 66, remains in clangorous and obstreperous form nearly 40 years after he first recorded with Ayler. There are times, in fact, that between the rumbles from his bass pedal and snare plus brush-directed scrambles from his ride cymbal that you have to sense more than hear Kowalds contributions. At the same time longtime Free Jazz followers may be surprised to hear the bassist introduce standard 4/4 time one-third of the way through Ya and direct the beat that way for the remainder of the track.

Although much of the reedists improvising starts in overdrive and goes on from there, his altissimo flurries and extended hocketing yowls add to excitement, as does the spetrofluctuation and key pops he exhibits on Da. At times he uses overblowing to generate intense honks or float tiny tunelets à la Sonny Rollins. Mixed with the squeals and flutter tonguing are some genuine melodies — one of which towards the end eerily and unintentionally resembles God Save The Queen — and on close listen, he sounds surprisingly straightahead.

Also unexpectedly restrained when he relaxes into it, Murrays ruffs and drags are focused with pinpoint accuracy to elicit dark-toned, four string bowing from Kowald, while his steady flams and rat tat tats meet lacerated string sounds and tiny, below-the-peg squeals from the bassman. Theres even a point where the drummer sounds out a definitive march tempo.

Double-pulsed guitar-like strums inform some of Kowalds work here, but his most characteristic trope occurs on Ka, where he moves nearly soundlessly to the foreground, stretching the strings with tiny bow movements, producing clicking sounds from below the bridge, as flinty reverberations fellow each thrust. Flailing vibrations create wailing tones that reify the mettle of those steel strings. At points the differentiated timbres created resemble those of a ngoni or African lute.

Xus guzheng or so-called Chinese zither is the real unconventional instrument on the four similarly titled improvisations that make up DEAR PETER. But such is the versatility of the 25-string machine — not to mention her technique honed by years of traditional study — that when not used in an Oriental manner, the zheng has tones that can resemble the Western double bass or 12-string guitar.

An example of this appears on Dear Peter part 3, where Schianos crooked alto tone encourages bowed accompaniment from the bass strings of Xus instrument. Plucking the strings with her right hand and touching the strings with her left hand to produce the desired pitch, she replicates the dark-toned bass scrawls of the European instrument. Subtly Blume uses rubbed drumsticks as his percussion contribution. Later when he mixes in more parts of his kit, flailing guitar-like noises appear from the zheng, though its as if she has a effects pedal underfoot, since her strings ring with what could be electrified distortion and delay. As he does in almost every performance, the altoist quotes Lover Man at this juncture, but considering the circumstances the lyric Oh lover man where can you be seems particularly apt.

The only other spot where the performance is particularly funereal is on Dear Peter part 1, where Xus keening vocal line and the harp-like glissandos from the zheng add up to intimations of a threnody — at least to Western ears. Its a good bet that followers of Chinese traditional music may not hear it the same way though, since at points her vocal, while definitely Oriental includes the strained delivery and guttural tones of a blues singer. Shes obviously as expressive with her voice as her axe. Schianos repeated honklets that ascend to high-pitched cries add to the mood, while Blumes percussion manages to approximate the sound of an African hollow log. Later on, a single bell peal may indeed reference Christian burial rites.

Three-sided conversation among accomplished improvisers, neither of these CDs should be limited to being heard as a dirge for a departed hero. Instead both are excellent demonstrations of Kowalds life force celebrated in proper settings.

Meanwhile life goes on. Younger improvisers like Xu and Tsahar show in their playing and associations in general that Kowalds welcoming of different forms of improvisation is ongoing.